1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Ftrace header. For implementation details beyond the random comments 4 * scattered below, see: Documentation/trace/ftrace-design.txt 5 */ 6 7 #ifndef _LINUX_FTRACE_H 8 #define _LINUX_FTRACE_H 9 10 #include <linux/trace_clock.h> 11 #include <linux/kallsyms.h> 12 #include <linux/linkage.h> 13 #include <linux/bitops.h> 14 #include <linux/ptrace.h> 15 #include <linux/ktime.h> 16 #include <linux/sched.h> 17 #include <linux/types.h> 18 #include <linux/init.h> 19 #include <linux/fs.h> 20 21 #include <asm/ftrace.h> 22 23 /* 24 * If the arch supports passing the variable contents of 25 * function_trace_op as the third parameter back from the 26 * mcount call, then the arch should define this as 1. 27 */ 28 #ifndef ARCH_SUPPORTS_FTRACE_OPS 29 #define ARCH_SUPPORTS_FTRACE_OPS 0 30 #endif 31 32 /* 33 * If the arch's mcount caller does not support all of ftrace's 34 * features, then it must call an indirect function that 35 * does. Or at least does enough to prevent any unwelcomed side effects. 36 */ 37 #if !ARCH_SUPPORTS_FTRACE_OPS 38 # define FTRACE_FORCE_LIST_FUNC 1 39 #else 40 # define FTRACE_FORCE_LIST_FUNC 0 41 #endif 42 43 /* Main tracing buffer and events set up */ 44 #ifdef CONFIG_TRACING 45 void trace_init(void); 46 void early_trace_init(void); 47 #else 48 static inline void trace_init(void) { } 49 static inline void early_trace_init(void) { } 50 #endif 51 52 struct module; 53 struct ftrace_hash; 54 55 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \ 56 defined(CONFIG_DYNAMIC_FTRACE) 57 const char * 58 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 59 unsigned long *off, char **modname, char *sym); 60 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 61 char *type, char *name, 62 char *module_name, int *exported); 63 #else 64 static inline const char * 65 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, 66 unsigned long *off, char **modname, char *sym) 67 { 68 return NULL; 69 } 70 static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, 71 char *type, char *name, 72 char *module_name, int *exported) 73 { 74 return -1; 75 } 76 #endif 77 78 79 #ifdef CONFIG_FUNCTION_TRACER 80 81 extern int ftrace_enabled; 82 extern int 83 ftrace_enable_sysctl(struct ctl_table *table, int write, 84 void __user *buffer, size_t *lenp, 85 loff_t *ppos); 86 87 struct ftrace_ops; 88 89 typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, 90 struct ftrace_ops *op, struct pt_regs *regs); 91 92 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops); 93 94 /* 95 * FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are 96 * set in the flags member. 97 * CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION_SAFE, STUB and 98 * IPMODIFY are a kind of attribute flags which can be set only before 99 * registering the ftrace_ops, and can not be modified while registered. 100 * Changing those attribute flags after registering ftrace_ops will 101 * cause unexpected results. 102 * 103 * ENABLED - set/unset when ftrace_ops is registered/unregistered 104 * DYNAMIC - set when ftrace_ops is registered to denote dynamically 105 * allocated ftrace_ops which need special care 106 * SAVE_REGS - The ftrace_ops wants regs saved at each function called 107 * and passed to the callback. If this flag is set, but the 108 * architecture does not support passing regs 109 * (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the 110 * ftrace_ops will fail to register, unless the next flag 111 * is set. 112 * SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the 113 * handler can handle an arch that does not save regs 114 * (the handler tests if regs == NULL), then it can set 115 * this flag instead. It will not fail registering the ftrace_ops 116 * but, the regs field will be NULL if the arch does not support 117 * passing regs to the handler. 118 * Note, if this flag is set, the SAVE_REGS flag will automatically 119 * get set upon registering the ftrace_ops, if the arch supports it. 120 * RECURSION_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure 121 * that the call back has its own recursion protection. If it does 122 * not set this, then the ftrace infrastructure will add recursion 123 * protection for the caller. 124 * STUB - The ftrace_ops is just a place holder. 125 * INITIALIZED - The ftrace_ops has already been initialized (first use time 126 * register_ftrace_function() is called, it will initialized the ops) 127 * DELETED - The ops are being deleted, do not let them be registered again. 128 * ADDING - The ops is in the process of being added. 129 * REMOVING - The ops is in the process of being removed. 130 * MODIFYING - The ops is in the process of changing its filter functions. 131 * ALLOC_TRAMP - A dynamic trampoline was allocated by the core code. 132 * The arch specific code sets this flag when it allocated a 133 * trampoline. This lets the arch know that it can update the 134 * trampoline in case the callback function changes. 135 * The ftrace_ops trampoline can be set by the ftrace users, and 136 * in such cases the arch must not modify it. Only the arch ftrace 137 * core code should set this flag. 138 * IPMODIFY - The ops can modify the IP register. This can only be set with 139 * SAVE_REGS. If another ops with this flag set is already registered 140 * for any of the functions that this ops will be registered for, then 141 * this ops will fail to register or set_filter_ip. 142 * PID - Is affected by set_ftrace_pid (allows filtering on those pids) 143 * RCU - Set when the ops can only be called when RCU is watching. 144 * TRACE_ARRAY - The ops->private points to a trace_array descriptor. 145 */ 146 enum { 147 FTRACE_OPS_FL_ENABLED = 1 << 0, 148 FTRACE_OPS_FL_DYNAMIC = 1 << 1, 149 FTRACE_OPS_FL_SAVE_REGS = 1 << 2, 150 FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = 1 << 3, 151 FTRACE_OPS_FL_RECURSION_SAFE = 1 << 4, 152 FTRACE_OPS_FL_STUB = 1 << 5, 153 FTRACE_OPS_FL_INITIALIZED = 1 << 6, 154 FTRACE_OPS_FL_DELETED = 1 << 7, 155 FTRACE_OPS_FL_ADDING = 1 << 8, 156 FTRACE_OPS_FL_REMOVING = 1 << 9, 157 FTRACE_OPS_FL_MODIFYING = 1 << 10, 158 FTRACE_OPS_FL_ALLOC_TRAMP = 1 << 11, 159 FTRACE_OPS_FL_IPMODIFY = 1 << 12, 160 FTRACE_OPS_FL_PID = 1 << 13, 161 FTRACE_OPS_FL_RCU = 1 << 14, 162 FTRACE_OPS_FL_TRACE_ARRAY = 1 << 15, 163 }; 164 165 #ifdef CONFIG_DYNAMIC_FTRACE 166 /* The hash used to know what functions callbacks trace */ 167 struct ftrace_ops_hash { 168 struct ftrace_hash __rcu *notrace_hash; 169 struct ftrace_hash __rcu *filter_hash; 170 struct mutex regex_lock; 171 }; 172 173 void ftrace_free_init_mem(void); 174 void ftrace_free_mem(struct module *mod, void *start, void *end); 175 #else 176 static inline void ftrace_free_init_mem(void) { } 177 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 178 #endif 179 180 /* 181 * Note, ftrace_ops can be referenced outside of RCU protection, unless 182 * the RCU flag is set. If ftrace_ops is allocated and not part of kernel 183 * core data, the unregistering of it will perform a scheduling on all CPUs 184 * to make sure that there are no more users. Depending on the load of the 185 * system that may take a bit of time. 186 * 187 * Any private data added must also take care not to be freed and if private 188 * data is added to a ftrace_ops that is in core code, the user of the 189 * ftrace_ops must perform a schedule_on_each_cpu() before freeing it. 190 */ 191 struct ftrace_ops { 192 ftrace_func_t func; 193 struct ftrace_ops __rcu *next; 194 unsigned long flags; 195 void *private; 196 ftrace_func_t saved_func; 197 #ifdef CONFIG_DYNAMIC_FTRACE 198 struct ftrace_ops_hash local_hash; 199 struct ftrace_ops_hash *func_hash; 200 struct ftrace_ops_hash old_hash; 201 unsigned long trampoline; 202 unsigned long trampoline_size; 203 #endif 204 }; 205 206 /* 207 * Type of the current tracing. 208 */ 209 enum ftrace_tracing_type_t { 210 FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */ 211 FTRACE_TYPE_RETURN, /* Hook the return of the function */ 212 }; 213 214 /* Current tracing type, default is FTRACE_TYPE_ENTER */ 215 extern enum ftrace_tracing_type_t ftrace_tracing_type; 216 217 /* 218 * The ftrace_ops must be a static and should also 219 * be read_mostly. These functions do modify read_mostly variables 220 * so use them sparely. Never free an ftrace_op or modify the 221 * next pointer after it has been registered. Even after unregistering 222 * it, the next pointer may still be used internally. 223 */ 224 int register_ftrace_function(struct ftrace_ops *ops); 225 int unregister_ftrace_function(struct ftrace_ops *ops); 226 void clear_ftrace_function(void); 227 228 extern void ftrace_stub(unsigned long a0, unsigned long a1, 229 struct ftrace_ops *op, struct pt_regs *regs); 230 231 #else /* !CONFIG_FUNCTION_TRACER */ 232 /* 233 * (un)register_ftrace_function must be a macro since the ops parameter 234 * must not be evaluated. 235 */ 236 #define register_ftrace_function(ops) ({ 0; }) 237 #define unregister_ftrace_function(ops) ({ 0; }) 238 static inline int ftrace_nr_registered_ops(void) 239 { 240 return 0; 241 } 242 static inline void clear_ftrace_function(void) { } 243 static inline void ftrace_kill(void) { } 244 static inline void ftrace_free_init_mem(void) { } 245 static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { } 246 #endif /* CONFIG_FUNCTION_TRACER */ 247 248 #ifdef CONFIG_STACK_TRACER 249 250 #define STACK_TRACE_ENTRIES 500 251 252 struct stack_trace; 253 254 extern unsigned stack_trace_index[]; 255 extern struct stack_trace stack_trace_max; 256 extern unsigned long stack_trace_max_size; 257 extern arch_spinlock_t stack_trace_max_lock; 258 259 extern int stack_tracer_enabled; 260 void stack_trace_print(void); 261 int 262 stack_trace_sysctl(struct ctl_table *table, int write, 263 void __user *buffer, size_t *lenp, 264 loff_t *ppos); 265 266 /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ 267 DECLARE_PER_CPU(int, disable_stack_tracer); 268 269 /** 270 * stack_tracer_disable - temporarily disable the stack tracer 271 * 272 * There's a few locations (namely in RCU) where stack tracing 273 * cannot be executed. This function is used to disable stack 274 * tracing during those critical sections. 275 * 276 * This function must be called with preemption or interrupts 277 * disabled and stack_tracer_enable() must be called shortly after 278 * while preemption or interrupts are still disabled. 279 */ 280 static inline void stack_tracer_disable(void) 281 { 282 /* Preemption or interupts must be disabled */ 283 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 284 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 285 this_cpu_inc(disable_stack_tracer); 286 } 287 288 /** 289 * stack_tracer_enable - re-enable the stack tracer 290 * 291 * After stack_tracer_disable() is called, stack_tracer_enable() 292 * must be called shortly afterward. 293 */ 294 static inline void stack_tracer_enable(void) 295 { 296 if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) 297 WARN_ON_ONCE(!preempt_count() || !irqs_disabled()); 298 this_cpu_dec(disable_stack_tracer); 299 } 300 #else 301 static inline void stack_tracer_disable(void) { } 302 static inline void stack_tracer_enable(void) { } 303 #endif 304 305 #ifdef CONFIG_DYNAMIC_FTRACE 306 307 int ftrace_arch_code_modify_prepare(void); 308 int ftrace_arch_code_modify_post_process(void); 309 310 struct dyn_ftrace; 311 312 enum ftrace_bug_type { 313 FTRACE_BUG_UNKNOWN, 314 FTRACE_BUG_INIT, 315 FTRACE_BUG_NOP, 316 FTRACE_BUG_CALL, 317 FTRACE_BUG_UPDATE, 318 }; 319 extern enum ftrace_bug_type ftrace_bug_type; 320 321 /* 322 * Archs can set this to point to a variable that holds the value that was 323 * expected at the call site before calling ftrace_bug(). 324 */ 325 extern const void *ftrace_expected; 326 327 void ftrace_bug(int err, struct dyn_ftrace *rec); 328 329 struct seq_file; 330 331 extern int ftrace_text_reserved(const void *start, const void *end); 332 333 extern int ftrace_nr_registered_ops(void); 334 335 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr); 336 337 bool is_ftrace_trampoline(unsigned long addr); 338 339 /* 340 * The dyn_ftrace record's flags field is split into two parts. 341 * the first part which is '0-FTRACE_REF_MAX' is a counter of 342 * the number of callbacks that have registered the function that 343 * the dyn_ftrace descriptor represents. 344 * 345 * The second part is a mask: 346 * ENABLED - the function is being traced 347 * REGS - the record wants the function to save regs 348 * REGS_EN - the function is set up to save regs. 349 * IPMODIFY - the record allows for the IP address to be changed. 350 * DISABLED - the record is not ready to be touched yet 351 * 352 * When a new ftrace_ops is registered and wants a function to save 353 * pt_regs, the rec->flag REGS is set. When the function has been 354 * set up to save regs, the REG_EN flag is set. Once a function 355 * starts saving regs it will do so until all ftrace_ops are removed 356 * from tracing that function. 357 */ 358 enum { 359 FTRACE_FL_ENABLED = (1UL << 31), 360 FTRACE_FL_REGS = (1UL << 30), 361 FTRACE_FL_REGS_EN = (1UL << 29), 362 FTRACE_FL_TRAMP = (1UL << 28), 363 FTRACE_FL_TRAMP_EN = (1UL << 27), 364 FTRACE_FL_IPMODIFY = (1UL << 26), 365 FTRACE_FL_DISABLED = (1UL << 25), 366 }; 367 368 #define FTRACE_REF_MAX_SHIFT 25 369 #define FTRACE_FL_BITS 7 370 #define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1) 371 #define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT) 372 #define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1) 373 374 #define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK) 375 376 struct dyn_ftrace { 377 unsigned long ip; /* address of mcount call-site */ 378 unsigned long flags; 379 struct dyn_arch_ftrace arch; 380 }; 381 382 int ftrace_force_update(void); 383 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 384 int remove, int reset); 385 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, 386 int len, int reset); 387 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 388 int len, int reset); 389 void ftrace_set_global_filter(unsigned char *buf, int len, int reset); 390 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 391 void ftrace_free_filter(struct ftrace_ops *ops); 392 void ftrace_ops_set_global_filter(struct ftrace_ops *ops); 393 394 enum { 395 FTRACE_UPDATE_CALLS = (1 << 0), 396 FTRACE_DISABLE_CALLS = (1 << 1), 397 FTRACE_UPDATE_TRACE_FUNC = (1 << 2), 398 FTRACE_START_FUNC_RET = (1 << 3), 399 FTRACE_STOP_FUNC_RET = (1 << 4), 400 }; 401 402 /* 403 * The FTRACE_UPDATE_* enum is used to pass information back 404 * from the ftrace_update_record() and ftrace_test_record() 405 * functions. These are called by the code update routines 406 * to find out what is to be done for a given function. 407 * 408 * IGNORE - The function is already what we want it to be 409 * MAKE_CALL - Start tracing the function 410 * MODIFY_CALL - Stop saving regs for the function 411 * MAKE_NOP - Stop tracing the function 412 */ 413 enum { 414 FTRACE_UPDATE_IGNORE, 415 FTRACE_UPDATE_MAKE_CALL, 416 FTRACE_UPDATE_MODIFY_CALL, 417 FTRACE_UPDATE_MAKE_NOP, 418 }; 419 420 enum { 421 FTRACE_ITER_FILTER = (1 << 0), 422 FTRACE_ITER_NOTRACE = (1 << 1), 423 FTRACE_ITER_PRINTALL = (1 << 2), 424 FTRACE_ITER_DO_PROBES = (1 << 3), 425 FTRACE_ITER_PROBE = (1 << 4), 426 FTRACE_ITER_MOD = (1 << 5), 427 FTRACE_ITER_ENABLED = (1 << 6), 428 }; 429 430 void arch_ftrace_update_code(int command); 431 432 struct ftrace_rec_iter; 433 434 struct ftrace_rec_iter *ftrace_rec_iter_start(void); 435 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter); 436 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter); 437 438 #define for_ftrace_rec_iter(iter) \ 439 for (iter = ftrace_rec_iter_start(); \ 440 iter; \ 441 iter = ftrace_rec_iter_next(iter)) 442 443 444 int ftrace_update_record(struct dyn_ftrace *rec, int enable); 445 int ftrace_test_record(struct dyn_ftrace *rec, int enable); 446 void ftrace_run_stop_machine(int command); 447 unsigned long ftrace_location(unsigned long ip); 448 unsigned long ftrace_location_range(unsigned long start, unsigned long end); 449 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); 450 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); 451 452 extern ftrace_func_t ftrace_trace_function; 453 454 int ftrace_regex_open(struct ftrace_ops *ops, int flag, 455 struct inode *inode, struct file *file); 456 ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 457 size_t cnt, loff_t *ppos); 458 ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 459 size_t cnt, loff_t *ppos); 460 int ftrace_regex_release(struct inode *inode, struct file *file); 461 462 void __init 463 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable); 464 465 /* defined in arch */ 466 extern int ftrace_ip_converted(unsigned long ip); 467 extern int ftrace_dyn_arch_init(void); 468 extern void ftrace_replace_code(int enable); 469 extern int ftrace_update_ftrace_func(ftrace_func_t func); 470 extern void ftrace_caller(void); 471 extern void ftrace_regs_caller(void); 472 extern void ftrace_call(void); 473 extern void ftrace_regs_call(void); 474 extern void mcount_call(void); 475 476 void ftrace_modify_all_code(int command); 477 478 #ifndef FTRACE_ADDR 479 #define FTRACE_ADDR ((unsigned long)ftrace_caller) 480 #endif 481 482 #ifndef FTRACE_GRAPH_ADDR 483 #define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller) 484 #endif 485 486 #ifndef FTRACE_REGS_ADDR 487 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 488 # define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller) 489 #else 490 # define FTRACE_REGS_ADDR FTRACE_ADDR 491 #endif 492 #endif 493 494 /* 495 * If an arch would like functions that are only traced 496 * by the function graph tracer to jump directly to its own 497 * trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR 498 * to be that address to jump to. 499 */ 500 #ifndef FTRACE_GRAPH_TRAMP_ADDR 501 #define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0) 502 #endif 503 504 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 505 extern void ftrace_graph_caller(void); 506 extern int ftrace_enable_ftrace_graph_caller(void); 507 extern int ftrace_disable_ftrace_graph_caller(void); 508 #else 509 static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; } 510 static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; } 511 #endif 512 513 /** 514 * ftrace_make_nop - convert code into nop 515 * @mod: module structure if called by module load initialization 516 * @rec: the mcount call site record 517 * @addr: the address that the call site should be calling 518 * 519 * This is a very sensitive operation and great care needs 520 * to be taken by the arch. The operation should carefully 521 * read the location, check to see if what is read is indeed 522 * what we expect it to be, and then on success of the compare, 523 * it should write to the location. 524 * 525 * The code segment at @rec->ip should be a caller to @addr 526 * 527 * Return must be: 528 * 0 on success 529 * -EFAULT on error reading the location 530 * -EINVAL on a failed compare of the contents 531 * -EPERM on error writing to the location 532 * Any other value will be considered a failure. 533 */ 534 extern int ftrace_make_nop(struct module *mod, 535 struct dyn_ftrace *rec, unsigned long addr); 536 537 /** 538 * ftrace_make_call - convert a nop call site into a call to addr 539 * @rec: the mcount call site record 540 * @addr: the address that the call site should call 541 * 542 * This is a very sensitive operation and great care needs 543 * to be taken by the arch. The operation should carefully 544 * read the location, check to see if what is read is indeed 545 * what we expect it to be, and then on success of the compare, 546 * it should write to the location. 547 * 548 * The code segment at @rec->ip should be a nop 549 * 550 * Return must be: 551 * 0 on success 552 * -EFAULT on error reading the location 553 * -EINVAL on a failed compare of the contents 554 * -EPERM on error writing to the location 555 * Any other value will be considered a failure. 556 */ 557 extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); 558 559 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS 560 /** 561 * ftrace_modify_call - convert from one addr to another (no nop) 562 * @rec: the mcount call site record 563 * @old_addr: the address expected to be currently called to 564 * @addr: the address to change to 565 * 566 * This is a very sensitive operation and great care needs 567 * to be taken by the arch. The operation should carefully 568 * read the location, check to see if what is read is indeed 569 * what we expect it to be, and then on success of the compare, 570 * it should write to the location. 571 * 572 * The code segment at @rec->ip should be a caller to @old_addr 573 * 574 * Return must be: 575 * 0 on success 576 * -EFAULT on error reading the location 577 * -EINVAL on a failed compare of the contents 578 * -EPERM on error writing to the location 579 * Any other value will be considered a failure. 580 */ 581 extern int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 582 unsigned long addr); 583 #else 584 /* Should never be called */ 585 static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, 586 unsigned long addr) 587 { 588 return -EINVAL; 589 } 590 #endif 591 592 /* May be defined in arch */ 593 extern int ftrace_arch_read_dyn_info(char *buf, int size); 594 595 extern int skip_trace(unsigned long ip); 596 extern void ftrace_module_init(struct module *mod); 597 extern void ftrace_module_enable(struct module *mod); 598 extern void ftrace_release_mod(struct module *mod); 599 600 extern void ftrace_disable_daemon(void); 601 extern void ftrace_enable_daemon(void); 602 #else /* CONFIG_DYNAMIC_FTRACE */ 603 static inline int skip_trace(unsigned long ip) { return 0; } 604 static inline int ftrace_force_update(void) { return 0; } 605 static inline void ftrace_disable_daemon(void) { } 606 static inline void ftrace_enable_daemon(void) { } 607 static inline void ftrace_module_init(struct module *mod) { } 608 static inline void ftrace_module_enable(struct module *mod) { } 609 static inline void ftrace_release_mod(struct module *mod) { } 610 static inline int ftrace_text_reserved(const void *start, const void *end) 611 { 612 return 0; 613 } 614 static inline unsigned long ftrace_location(unsigned long ip) 615 { 616 return 0; 617 } 618 619 /* 620 * Again users of functions that have ftrace_ops may not 621 * have them defined when ftrace is not enabled, but these 622 * functions may still be called. Use a macro instead of inline. 623 */ 624 #define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) 625 #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) 626 #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) 627 #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) 628 #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) 629 #define ftrace_free_filter(ops) do { } while (0) 630 #define ftrace_ops_set_global_filter(ops) do { } while (0) 631 632 static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, 633 size_t cnt, loff_t *ppos) { return -ENODEV; } 634 static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf, 635 size_t cnt, loff_t *ppos) { return -ENODEV; } 636 static inline int 637 ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; } 638 639 static inline bool is_ftrace_trampoline(unsigned long addr) 640 { 641 return false; 642 } 643 #endif /* CONFIG_DYNAMIC_FTRACE */ 644 645 /* totally disable ftrace - can not re-enable after this */ 646 void ftrace_kill(void); 647 648 static inline void tracer_disable(void) 649 { 650 #ifdef CONFIG_FUNCTION_TRACER 651 ftrace_enabled = 0; 652 #endif 653 } 654 655 /* 656 * Ftrace disable/restore without lock. Some synchronization mechanism 657 * must be used to prevent ftrace_enabled to be changed between 658 * disable/restore. 659 */ 660 static inline int __ftrace_enabled_save(void) 661 { 662 #ifdef CONFIG_FUNCTION_TRACER 663 int saved_ftrace_enabled = ftrace_enabled; 664 ftrace_enabled = 0; 665 return saved_ftrace_enabled; 666 #else 667 return 0; 668 #endif 669 } 670 671 static inline void __ftrace_enabled_restore(int enabled) 672 { 673 #ifdef CONFIG_FUNCTION_TRACER 674 ftrace_enabled = enabled; 675 #endif 676 } 677 678 /* All archs should have this, but we define it for consistency */ 679 #ifndef ftrace_return_address0 680 # define ftrace_return_address0 __builtin_return_address(0) 681 #endif 682 683 /* Archs may use other ways for ADDR1 and beyond */ 684 #ifndef ftrace_return_address 685 # ifdef CONFIG_FRAME_POINTER 686 # define ftrace_return_address(n) __builtin_return_address(n) 687 # else 688 # define ftrace_return_address(n) 0UL 689 # endif 690 #endif 691 692 #define CALLER_ADDR0 ((unsigned long)ftrace_return_address0) 693 #define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1)) 694 #define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2)) 695 #define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3)) 696 #define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4)) 697 #define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5)) 698 #define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6)) 699 700 static inline unsigned long get_lock_parent_ip(void) 701 { 702 unsigned long addr = CALLER_ADDR0; 703 704 if (!in_lock_functions(addr)) 705 return addr; 706 addr = CALLER_ADDR1; 707 if (!in_lock_functions(addr)) 708 return addr; 709 return CALLER_ADDR2; 710 } 711 712 #ifdef CONFIG_IRQSOFF_TRACER 713 extern void time_hardirqs_on(unsigned long a0, unsigned long a1); 714 extern void time_hardirqs_off(unsigned long a0, unsigned long a1); 715 #else 716 static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { } 717 static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { } 718 #endif 719 720 #if defined(CONFIG_PREEMPT_TRACER) || \ 721 (defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_PREEMPTIRQ_EVENTS)) 722 extern void trace_preempt_on(unsigned long a0, unsigned long a1); 723 extern void trace_preempt_off(unsigned long a0, unsigned long a1); 724 #else 725 /* 726 * Use defines instead of static inlines because some arches will make code out 727 * of the CALLER_ADDR, when we really want these to be a real nop. 728 */ 729 # define trace_preempt_on(a0, a1) do { } while (0) 730 # define trace_preempt_off(a0, a1) do { } while (0) 731 #endif 732 733 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 734 extern void ftrace_init(void); 735 #else 736 static inline void ftrace_init(void) { } 737 #endif 738 739 /* 740 * Structure that defines an entry function trace. 741 * It's already packed but the attribute "packed" is needed 742 * to remove extra padding at the end. 743 */ 744 struct ftrace_graph_ent { 745 unsigned long func; /* Current function */ 746 int depth; 747 } __packed; 748 749 /* 750 * Structure that defines a return function trace. 751 * It's already packed but the attribute "packed" is needed 752 * to remove extra padding at the end. 753 */ 754 struct ftrace_graph_ret { 755 unsigned long func; /* Current function */ 756 /* Number of functions that overran the depth limit for current task */ 757 unsigned long overrun; 758 unsigned long long calltime; 759 unsigned long long rettime; 760 int depth; 761 } __packed; 762 763 /* Type of the callback handlers for tracing function graph*/ 764 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ 765 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ 766 767 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 768 769 /* 770 * Stack of return addresses for functions 771 * of a thread. 772 * Used in struct thread_info 773 */ 774 struct ftrace_ret_stack { 775 unsigned long ret; 776 unsigned long func; 777 unsigned long long calltime; 778 #ifdef CONFIG_FUNCTION_PROFILER 779 unsigned long long subtime; 780 #endif 781 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST 782 unsigned long fp; 783 #endif 784 #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 785 unsigned long *retp; 786 #endif 787 }; 788 789 /* 790 * Primary handler of a function return. 791 * It relays on ftrace_return_to_handler. 792 * Defined in entry_32/64.S 793 */ 794 extern void return_to_handler(void); 795 796 extern int 797 ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, 798 unsigned long frame_pointer, unsigned long *retp); 799 800 unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, 801 unsigned long ret, unsigned long *retp); 802 803 /* 804 * Sometimes we don't want to trace a function with the function 805 * graph tracer but we want them to keep traced by the usual function 806 * tracer if the function graph tracer is not configured. 807 */ 808 #define __notrace_funcgraph notrace 809 810 #define FTRACE_NOTRACE_DEPTH 65536 811 #define FTRACE_RETFUNC_DEPTH 50 812 #define FTRACE_RETSTACK_ALLOC_SIZE 32 813 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, 814 trace_func_graph_ent_t entryfunc); 815 816 extern bool ftrace_graph_is_dead(void); 817 extern void ftrace_graph_stop(void); 818 819 /* The current handlers in use */ 820 extern trace_func_graph_ret_t ftrace_graph_return; 821 extern trace_func_graph_ent_t ftrace_graph_entry; 822 823 extern void unregister_ftrace_graph(void); 824 825 extern void ftrace_graph_init_task(struct task_struct *t); 826 extern void ftrace_graph_exit_task(struct task_struct *t); 827 extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu); 828 829 static inline int task_curr_ret_stack(struct task_struct *t) 830 { 831 return t->curr_ret_stack; 832 } 833 834 static inline void pause_graph_tracing(void) 835 { 836 atomic_inc(¤t->tracing_graph_pause); 837 } 838 839 static inline void unpause_graph_tracing(void) 840 { 841 atomic_dec(¤t->tracing_graph_pause); 842 } 843 #else /* !CONFIG_FUNCTION_GRAPH_TRACER */ 844 845 #define __notrace_funcgraph 846 847 static inline void ftrace_graph_init_task(struct task_struct *t) { } 848 static inline void ftrace_graph_exit_task(struct task_struct *t) { } 849 static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { } 850 851 static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc, 852 trace_func_graph_ent_t entryfunc) 853 { 854 return -1; 855 } 856 static inline void unregister_ftrace_graph(void) { } 857 858 static inline int task_curr_ret_stack(struct task_struct *tsk) 859 { 860 return -1; 861 } 862 863 static inline unsigned long 864 ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, 865 unsigned long *retp) 866 { 867 return ret; 868 } 869 870 static inline void pause_graph_tracing(void) { } 871 static inline void unpause_graph_tracing(void) { } 872 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 873 874 #ifdef CONFIG_TRACING 875 876 /* flags for current->trace */ 877 enum { 878 TSK_TRACE_FL_TRACE_BIT = 0, 879 TSK_TRACE_FL_GRAPH_BIT = 1, 880 }; 881 enum { 882 TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT, 883 TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT, 884 }; 885 886 static inline void set_tsk_trace_trace(struct task_struct *tsk) 887 { 888 set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 889 } 890 891 static inline void clear_tsk_trace_trace(struct task_struct *tsk) 892 { 893 clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace); 894 } 895 896 static inline int test_tsk_trace_trace(struct task_struct *tsk) 897 { 898 return tsk->trace & TSK_TRACE_FL_TRACE; 899 } 900 901 static inline void set_tsk_trace_graph(struct task_struct *tsk) 902 { 903 set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 904 } 905 906 static inline void clear_tsk_trace_graph(struct task_struct *tsk) 907 { 908 clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace); 909 } 910 911 static inline int test_tsk_trace_graph(struct task_struct *tsk) 912 { 913 return tsk->trace & TSK_TRACE_FL_GRAPH; 914 } 915 916 enum ftrace_dump_mode; 917 918 extern enum ftrace_dump_mode ftrace_dump_on_oops; 919 extern int tracepoint_printk; 920 921 extern void disable_trace_on_warning(void); 922 extern int __disable_trace_on_warning; 923 924 int tracepoint_printk_sysctl(struct ctl_table *table, int write, 925 void __user *buffer, size_t *lenp, 926 loff_t *ppos); 927 928 #else /* CONFIG_TRACING */ 929 static inline void disable_trace_on_warning(void) { } 930 #endif /* CONFIG_TRACING */ 931 932 #ifdef CONFIG_FTRACE_SYSCALLS 933 934 unsigned long arch_syscall_addr(int nr); 935 936 #endif /* CONFIG_FTRACE_SYSCALLS */ 937 938 #endif /* _LINUX_FTRACE_H */ 939